Door latch

ABSTRACT

THE DOOR LATCH IS OF THE DEAD-BOLT TYPE IN WHICH THE BOLT MAY NOT BE RETRACTED EXCEPT UPON PIVOTING OF AN ACTUATOR PROVIDED WITHIN THE LATCH HOUSING. THE ACTUATOR IS KEY OPERATED ON ONE SIDE, NORMALLY THE EXTERIOR SURFACE OF THE DOOR, AND IS MANUALLY ACTUATABLE ON THE OTHER, OR INTERIOR, SIDE OF THE DOOR. THE DOOR LATCH INCLUDES A HOUSING IN WHICH ARE MOUNTED THE BOLT AND BOLT ACTUATING COMPONENTS. THE COMPONENTS ARE FEW IN NUMBER TO PROVIDE A SIMPLE BUT EFFECTIVE LOCKING DEVICE.

G. WARTIAN DOOR LATCH Nov. 30, 1971 2 Shects-Shoct l Filed Nov. 20. 1969 FIG.

INVENTUM?. GEORGE WARTIAN BY i ATTORNEYS Nov. 30, 1971 G. WARTIAN 3,623,344

DOOR LATCH boots-Shoot 2 Filed NOV. 20, 1969 INVENTOR. GEORGE WARTIAN ATTORNEYS United States Patent O 3,623,344 DOOR LATCH George Wartian, East Detroit, Mich., assigner to Wartian Lock Company, St. Clair Shores, Mich. Filed Nov. 2G, 1969, Ser. No. 878,362 Int. Cl. EOSb 65/06 U.S. Cl. 70-134 2 Claims ABSTRACT OF THE DISCLOSURE The door latch is of the dead-bolt type in which the bolt may not be retracted except upon pivoting of an actuator provided within the latch housing. The actuator is key operated on one side, normally the exterior surface of the door, and is manually actuatable on the other, or interior, side of the door. The door latch includes a housing in which are mounted the bolt and bolt actuating components. The components are few in number to provide a simple but effective locking device,

BACKGROUND OF THE INVENTION In recent years, 'various types of house trailers and campers have come into widespread use. Such trailer constructions require compact and inexpensive latching means for the hinged doors thereof. Many door latch structures provided in the past have either been too bulky for use in connection with trailer constructions or, if compact, have been too expensive for use in connection with the relatively inexpensive trailer structures.

In accordance with the present invention, a door latch is provided which is both compact and inexpensive. Additionally, the door latch is reliable and durable in use and is easily assembled and mounted on the doors provided in such trailer constructions.

SUMMARY OF THE INVENTION The door latch comprises a housing in which a bolt is slidably supported. The housing also includes a pivotable actuator for extending and retracting the bolt. Spring urged latching means are provided in the housing. The latching means are effective to positively lock the bolt in the extended position and to frictionally lock the bolt in the retracted position. A clearance is provided between the bolt and the actuator to permit pivoting of the actuator for a short arc in a direction to retract the bolt before contact of the actuator and bolt. The actuator includes cam structure for contact with the latching means during said arc to disengage the latching means from the bolt and thereby permit retraction of the bolt upon further pivoting of the actuator.

In the drawings:

FIG` 1 is a view in perspective of one embodiment of the door latch of the present invention;

FIG. 2 is an exploded view of the door latch of FIG. 1;

FIG. 3 is a view in perspective of the bolt for the door latch of FIG. 1;

FIG. 4 is a view of the door latch with part of the casing removed illustrating the position of the components with the bolt retracted;

FIG. 5 is a view similar to FIG. 4 illustrating the position of the components when retraction of the bolt is initiated; and

FIG. 6 is a view similar to FIG. 4 illustrating partial extension of the bolt.

Referring to FIGS. 1, 2 and 3, the door latch 10 is adapted to be mounted on a relatively thick door such as may be found in, for example, a camping trailer or the like` 'The door latch 10 has an extendable and retractable bolt 12 adapted to be received in the recess provided in a conventional striker plate mounted on the door frame. A key operated cylinder 14 and key 16 are provided for actuation of the door latch from the exterior or outside of the door. It will be noted that the cylinder 14 is mounted in a relatively long sleeve 46 so that it will extend completely through a camper door, camper doors being relatively thick to provide interior space for insulating material. A pivotal lever 18 is provided on the interior or inside portion of the door latch 10 to permit manual unlatching from the inside without use of a key.

The door latch 10 includes a casing comprising two halves 2t), 22 which tit together to form an interior space which contains the locking mechanism. The casing halves are generally rectangular and each comprises a back Wall 24, 26, upstanding side walls 28, 30 and 32, 34, and upstanding end Walls 36, 38 and 40, 42. The interior dimensions of casing half 22 are slightly larger than the exterior dimensions of casing half 2t) so that casing half 20 will iit into casing half 22. Registering openings are provided in the corners of the casing halves to receive screws 44 which extend through the opening means and into threading engagement with the interior surface of the door upon which the latch is mounted to thereby secure the door latch components together and the door latch to the door.

The key operated cylinder 14 is mounted in the hollow cylindrical sleeve 46 which extends from back wall 24 of casing half 20. The cylinder 14 extends for approximately half the length of the sleeve 46 and has a projection 50 which extends for a further distance into the sleeve 46 but terminates short of the inner end thereof. The projection 50 is generally square in cross-section with each corner having a small ear-like projection for firm locking engagement with the interior surface of a recess 52 provided in one end of cylindrical element S4. The recess 52 is also generally square in cross-section.

A pair of spaced apart diametrically opposed pins 56, 58 extend outwardly from the inner end of the cylindrical element 54 for engagement with similar pins 60, 62 provided on one end of the actuator 64. The cylindrical element 54 is received within the sleeve 46 with the projection 50 received in and in engagement with the interior sur* faces of the recess 52. When the cylindrical element 54 is positioned within the sleeve 46 there is still a space between the inner end of the cylindrical element and the inner end of the sleeve for reception of cylindrical portion 66 of the actuator 64. As will be noted, the actuator 64 has a cam element 68 which extends outwardly at substantially right angles to the longitudinal axis thereof at about the center of the actuator body. The cylindrical element 54 is positioned on the projection 50 in a manner to locate the pins 56, 58 vertically between the pins 60, 62 which are oriented in a horizontal plane so that the cam element 68 will assume the orientation illustrated. As will be noted in FIG. 6, the pins 60, 62 are offset counterclockwise from the longitudinal center of the cam element 68. This arrangement provides the desired operating clearance for pivoting of the actuator 64 by means of the key operated cylinder 14 to permit pivoting of the cylinder after extending or retracting the bolt to align the cylinder mechanism thus allowing removal of the key therefrom.

The actuator 64 includes a hollow cylindrical portion 70 which extends axially outwardly from the portion 66. A recess 72, which is generally square in cross-section, is provided in the end of the cylindrical portion 70 to receive mating projection 74 of lever 18. The projection 74 extends through an opening 76 provided in the back wall 26 of casing half 22. Upon engagement of the projection 74 with the recess 72, the lever 18 may be used to manually turn the actuator 64. An actuating lever 80 extends outwardly from the exterior of the cylindrical portion 70 at substantially right angles to the plane of cam element 68.

The function of the actuator 64 is to extend and retract the bolt 12. The bolt 12 has a recess 82 on one side edge thereof to receive the lever 89. The side surfaces 84, 86 of the recess 82 are in alignment with the lever 80 and make contact therewith during portions of the bolt movement. The outermost portion of the cam element 68 is generally V-shaped dening a pair of cam surfaces 88, 90. The cam surfaces are effective to cammingly engage the curved forward end 92 of a finger 94 forming part of the latching element `96. The cam surface 88 is also effective to cammingly engage a wall 98 provided on the under surface of the boit 12 to cammingly drive the bolt to the extended position. As will be noted, the bolt 12 is extendable through an opening 100 provided in the side of the casing. The Wall 98 also serves as a stop member which contacts the casing side wall during extension of the bolt to limit the travel of the bolt. Travel of. the bolt in the opposite or retracted position is limited by engagement of the bolt with the opposite casing side Wall.

A guide slot 102 is provided in the underside of the bolt 12. The guide slot 102 is received on a pair of spaced apart projections 194, 106 which extend from the inner surface of the back wall 24 of the casing half 20. This configuration guides the bolt in its back and forth movement. A foot element 108, 110, 112 is provided at three corners of slot 102. These feet, along with the wall 98, serve to space the bolt 12 from the back wall 24 of casing half 20. The space thus provided permits movement of the cam element 68 and latch finger 94 beneath the bolt 12.

The latching element 96 has an enlarged portion 114 adjacent to the ringer 94. The construction is such that the latching element has a generally L-shaped appearance when viewed from the side. The enlarged portion 114 engages a projection 116 on the edge of the bolt 12 to maintain the holt in the extended or retracted position. The inner side surface 118 of the projection 116 is relatively straight and is relatively deep so that when the enlarged portion 114 is biased towards the bolt by means of a spring 129 to engage the bolt, the bolt may not be retracted until the latching element 96 is moved out of engagement therewith by means of the actuator 64. This results in what is termed a dead bolt construction. The other side surface 122 of the projection 116 is a relatively gentle curve. When the bolt is retracted and the enlarged portion 114 engages the surface 122, the bolt may be extended without first disengaging the enlarged portion. The force exerted on the bolt 12 by means of the actuator 64 tending to extend the bolt will result in camming engagement of the surface 122 with the enlarged portion 114 to thus disengage these elements and permit extension of the bolt 12. As will be noted, the latching element 96 is received in a ehannei defined by wall portions 124, 126 which are at substantially right angles to the path of travel of the bolt 12. The channel dened by the walls 124, 126 serves as the guide for the latching element `96 and as a retainer for the latching element and the spring 120.

Operation of the door latch may now be completely understood. FIG. 4 illustrates the door latch with the bolt 12 completely retracted to permit opening and closing of the door upon which the door latch is mounted. The actuator 64 is illustrated in its iinal position at the end of retraction of the bolt 12. As will be appreciated, the actuator 64 may be moved to this position either by means of the lever 18 or the key operated exterior cylinder 14. The lever 18 results in direct pivoting of the actuator 64. The key operated cylinder 14 causes pivoting of the actuator 64 via engagement of the pins S6, 58 of the cylinder 54 with the pins 66, 62 of the actuator 64. As will be noted, upon complete retraction of the bolt 12, the latching element 96 is biased by the spring 120 to place enlarged portion 114 into engagement with the edge of the bolt 12 at a position where it will engage the surface 122 of projection 116 and prevent inadvertent extension of 4 the bolt 12. However, the bolt 12 may be extended without rst moving the latching element 96 out of engagement with the surface 122 as previously explained.

When it is wished to extend the bolt, the actuator 64 is pivoted in the counterclockwise direction as viewed in FIGS. 4 and 6. Before the cam surface 88 makes contact with the forward end 92 of the latching element 96, the side surface 128 of the cam element 68 will engage the wall 98 of the bolt 12, driving the bolt 12 to the left as viewed in FIG. 4. This results in the enlarged portion 114 of latching element 96 being cammed out of engagement with the bolt projection 116. As will be noted in FIG. y6, the projection 116 has passed partially by the enlarged portion 114 by the time the tip of the cam element 68 would make engagement with the end 92 of finger 94. Turning of the actuator 64 further in the counterclockwise direction as viewed in FIG. 6 will result in the lever contacting the surface 84 to drive the bolt 12 to the fully extended position shown in FIG. 5 wherein the wall 98 Will engage the wall portion 99 of the casing half 20. At this point, the spring 120 will drive the latching element 96 forwardly to engage the enlarged portion 114 with the surface 118 of projection 116 and prevent retraction of the bolt except upon pivoting of the actuator in the reverse or clockwise direction.

Upon pivoting of the actuator 64 in the clockwise direction, the cam surface will contact the end 92 of finger 94 before any other portion of the bolt 12 is contacted by the actuator. The cam surface 90 cams the latching element 96 rearwardly to move enlarged portion 114 out of engagement with the bolt 12 as illustrated in FIG. 5. At this point, the lever 80 contacts the surface 86 of the recess 82. Continued pivoting of the actuator 64 will then move the bolt 12 to the right as seen in FIG. 5. As soon as a portion of the projection 116 of the bolt is in line with the enlarged portion 114 of the latching element 96, the tip 130 of the cam element 68 passes beyond the end 92 of finger 94, thus permitting the spring to bias the latching element 96 against the bolt. However, at this time the projection 116 will hold the latching element back until it has entirely passed thereby. Continued pivoting of the actuatol 64 will drive the bolt to its fully retracted position as shown in FIG. 4 whereupon the latching element 96 will be biased forwardly by spring 120 to again cause the enlarged portion 114 to engage the projection 116 thus maintaining the holt in its retracted position.

What I claim as my invention is:

1. A door iatch comprising a housing, a bolt slidably supported in the housing, a single actuator pivotally mounted in the housing for pivoting on an axis substantially perpendicular to the plane of the bolt for extending and retracting the bolt, a manually turnable element on one exterior side of the housing in engagement with the pivotable actuator for manually extending and retracting the bolt, key actuated means on the opposite side of the housing in engagement with the actuator to pivot the actuator from the opposite side of the housing, said manually turnable element and said key actuated means being mounted to pivot on axes coaxial with the axis of said actuator, said bolt having a recess in one side thereof, said actuator having a single cam lever extending into the recess at substantially right angles to the plane of the bolt and contactable with opposed surfaces thereof to cammingly drive the bolt for extension and retraction thereof, said bolt having a projection on the other side thereof, spring urged latching means including an enlarged portion on said other side of the bolt biased toward the bolt and contactable with the surface thereof adjacent to said projection to engage alternate sides of the projection to lock the bolt in the extended or retracted position, said bolt being spaced from the housing, said spring urged latching means having a finger extending between the bolt and the housing towards the actuator, said actuator having a portion with a Acam surface at substantially right angles to said cam lever and extending between the bolt and the housing towards the finger, said cam surface cammingly engaging the linger, said spring urged latching means being effective to positively lock the bolt in the extended position, said cam surface cammingly engaging the finger prior to contact of the cam lever with the bolt when the actuator is pivoted to retract the bolt to disengage the latching means from the bolt prior to retracting the bolt, said recess in the bolt defining a clearance between the bolt and said cam lever of the actuator permitting pivoting of said actuator for a short arc in a direction to retract the bolt before contact of said cam lever and bolt.

2. A door latch as defined in claim 1, and further characterized in that said projection includes a cam surface on the side opposite said positive engagement side, said spring urged latching means being effective to cammingly engage said cam surface on the bolt projection upon retraction of the bolt to frictionally maintain 6 the bolt in the retracted position whereby the bolt may be exended prior to contact of the cam lever therewith with the spring urged latching means being cammed by the projection out of obstruction with the projection.

References Cited UNITED STATES PATENTS 1,480,181 1/1924 Mueller 292-150 UX 1,564,463 12/1925 Best 70-379 UX FOREIGN PATENTS 855,898 2/1940 France 7G-134 945,767 12/1948 France 70-134 ALBERT G. CRAIG, JR., Primary Examiner U.S. Cl. X.R.

70-DIG 6, DIG 42; 292-150 

